Last Modified: 07-31-2024 6.11:8.1.0 Doc ID: RM1000000028C4F
Model Year Start: 2023 Model: GR Corolla Prod Date Range: [11/2022 -           ]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model with Automatic Air Conditioning System): Weak Blower Output; 2023 - 2025 MY Corolla Corolla Hatchback GR Corolla [11/2022 -        ]

Weak Blower Output

DESCRIPTION

If the airflow from the registers is weak regardless of the blower speed setting displayed on the air conditioning control assembly, the following factors may be the cause.

Symptom

Factor
  • Airflow volume is constantly low
  • Airflow volume sometimes becomes low
  • ECO mode control of air conditioning system is enabled
  • Blower motor with fan sub-assembly malfunction
  • Clogged clean air filter
  • Clogged No. 1 cooler evaporator sub-assembly or heater radiator unit sub-assembly fins
  • Evaporator temp. sensor (No. 1 cooler thermistor) not connected properly
  • Aspirator pipe not connected properly

PROCEDURE

1.

CHECK AIR CONDITIONING SYSTEM

(a) Operate the blower switch with the following conditions met and check that the airflow volume changes.

Blower Speed

Condition

LO → HI
  • Temperature setting: MAX COLD
  • Air outlet mode: FACE
  • A/C switch: Off

OK:

Airflow volume increases.

NG

GO TO OTHER DIAGNOSIS PROCEDURE (Blower Motor Circuit)

OK

2.

CHECK ECO MODE SETTING

(a) Confirm that ECO HEAT/COOL switch (air conditioning control assembly) is set to off.

(b) Confirm that ECO drive mode is set to off.

HINT:

When the ECO drive mode is set to ON, the air conditioning amplifier assembly performs minimal air conditioning control in order to promote the improvement of fuel economy. Ensure that the customer understands that the airflow volume will be decreased compared to normal operation.

Control

Control Summary

Air Volume Control

Sets the blower level to less.
NEXT

3.

CHECK CLEAN AIR FILTER

(a) Visually check the clean air filter.

OK:

The clean air filter is not dirty or clogging.

NG

REPLACE CLEAN AIR FILTER

OK

4.

CHECK EVAPORATOR TEMP. SENSOR (NO. 1 COOLER THERMISTOR)

(a) Check the installation condition of the evaporator temp. sensor (No. 1 cooler thermistor).

OK:

Evaporator temp. sensor (No. 1 cooler thermistor) is installed correctly.

NG

REINSTALL EVAPORATOR TEMP. SENSOR (NO. 1 COOLER THERMISTOR)

OK

5.

CHECK ASPIRATOR PIPE

(a) Check the installation condition of the aspirator pipe.

OK:

The aspirator pipe is installed correctly.

OK

REPLACE HEATER RADIATOR UNIT SUB-ASSEMBLY OR NO. 1 COOLER EVAPORATOR SUB-ASSEMBLY

NG

INSTALL ASPIRATOR PIPE